Photographic emulsion



Patented Apr. 21, 1936 UNITED STATES PATENT OFFICE PHOTOGRAPHIC EMULSION Orry Charles Morrison, Carroll, Iowa No Drawing. Application August 15, 1934,

Serial No. 739,984

4 Claims. (01. 95-7) One of the objects of the invention is to pro- Freshly distilled water .034 oz. vide an improved photographic emulsion which is Gelatin 1 gr. particularly sensitive to light colors. Silver nitrate 0.4 gr.

Another object of the invention is to provide Potassium bromide 0.2 gr.

5 a gelatin emulsion which may be readily prepared Sodium bromide 0.2 gr. 5

and utilized in connection with photographic Ammonium bromide 0.2 gr.

The preferred method of carrying out the invention is as follows:

The gelatin preferably employed is from the young, yet mature, bovine type. It must be prepared so that it is free from impurities of whatever kind. The distilled water used for making y the emulsion must be freshly distilled and kept free from direct sunlight, and in a cool place. The silver nitrate and halogens shall be selected as chemically pure products.

To the emulsion thus prepared from gelatin, distilled water, silver nitrate, and said halogen compounds, the following color chemicals are preferably added in the following proportions as This amount is allowed per square inch of film surface exposed and the surplus accounts for evaporation and loss in material in handling. 10

What I claim as my invention and desire to secure by Letters Patent is:

1. A photographic emulsion comprising gelatin, silver nitrate, a halide of rubidium, a halide of caesium, chromous hydroxide and thallium hydroxide.

2. A photographic emulsion which comprises gelatin, silver nitrate, rubidium bromide, chromous hydroxide, hydroxide of thallium, caesium bromide and chromous alum.

3. A photographic emulsion comprising gelatin, silver nitrate, a halide of rubidium, a halide indicated. of caesium, chromous hydroxide, thallium hy- Grain drate and chromous alum.

Rubidium bromide, for red, -0.1 4. A photographic emulsion comprising the fol- 5 Chromous hydroxide, for yellow, 0.1 lowing ingredients in substantially the following Thallium hydrate, for green, 0.1 proportions:

Caesium bromide, for blue, 0.1 Chromous alum, for purple, 0.1 32 2 15 Water 2,3

The photochemicals are weighed and dissolved Silver nitrate 0.4 gr. 30

in a small quantity of the distilled water and Potassium bromide 0.2 gr. gelatin, and are added to the media, beginning Sodium bromide 0.2 gr. preferably with the purple and stirring continu- Ammonium bromide 0.2 gr.

35 ously, and each is added in succession from the Rubidium bromide 35 purple to the red, and this is done in absolute Chmmous hYdmXlde darkness Thallium hydrate 0.1 gr.

As an example of the emulsions usable, the Caesmm bromlde Chromous alum 0.1 gr.

above color chemicals may be added to an emulsion comprising, 

